<html>
<head>
	<title>sdasda</title>
	<meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1">
	<script src="https://cdn.jsdelivr.net/npm/vue"></script>
	<style>
		
	</style>
</head>
<body>
	<div id="app">
	    <p>{{ foo }}</p>
	    <!-- 这里的 `foo` 不会更新！ -->
	    <button v-on:click="foo = 'baz'">Change it</button>
	</div>
</body>
<script>
	var data = { foo: 1 }
	var vm = new Vue({
	  el: '#app',
	  data: data
	})
</script>
</html>